Apart from loving to play and watch football, I have also been interested in how the balls are constructed. Today there are many different constructions. For example, the FIFA World Cup official match balls have evolved over the years. The football panels were originally hand stitched together, using genuine leather, but in the 1970s, they changed to a synthetic leather that would not absorb water, preventing it from getting heavy (because the leather would absorb the water). Then in the early 2000s, the way that the panels are joined together have evolved (a breakthrough in technology), where the panels are laminated onto a rubber inner bladder. The lamination creates a watertight construction, there are no stitch holes, which does not allow any water to get in. The average weight of the size 5 football has been from 420-440 grams. The circumference is from 685-695 mm. The football has a very tight tolerance, being 1.5%. Besides this, there are many different constructions for different playing grounds, like indoor, artificial turf, beach, winter, etc.